Method and user equipment (ue) for managing harq procedure for multiple numerologies

ABSTRACT

Embodiments herein provide a method for managing HARQ procedure for multiple numerologies multiplexing in a wireless communication network. The method includes transmitting, by a User Equipment (UE), capability parameters of the UE to a Base Station (BS). Further, the method includes receiving, by the UE, a plurality of HARQ configuration parameters corresponding to the capability parameters of the UE from the BS, and perfuming, by the UE, one of an individual HARQ process and a shared HARQ process based on the plurality of HARQ configuration parameters received from the BS.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 16/483,964,which is the National Phase Entry of PCT International Application No.PCT/KR2018/001612, filed Feb. 6, 2018, and claims priority to IndianProvisional Patent Application No. 201741004273 filed on Feb. 6, 2017and Indian Complete Patent Application No. 201741004273 filed on Feb. 5,2018 in the Indian Intellectual Property Office, the contents of whichare incorporated herein by reference.

BACKGROUND 1. Field

The embodiments herein generally relate to wireless communicationnetwork. More particularly, related to a method and User Equipment (UE)for managing Hybrid Automatic Repeat Request (HARQ) procedure formultiple numerologies multiplexing in the wireless communicationnetwork.

2. Description of the Related Art

The 5th generation (5G) telecommunication is expected to support widerange of services including enhanced mobile broadband, ultra reliableand low latency communication, massive machine type communications, etc.Each service has its own specific set of requirements, which is expectedto be catered by the cellular network. For instance, enhanced mobilebroadband requires high speed of data transfer, ultra reliable lowlatency communication requires data transfer with very low latency butmay not require high data rate, while massive machine typecommunications may have the requirement to minimize User Equipment (UE)power consumption. In order to cater for different requirements, thecellular network can partition radio resources such that each set ofradio resources can meet the requirements of a given service by usingdifferent physical layer configurations.

In 5G system, it would be possible for the UE to access multipleservices concurrently, hence Radio Access Network (RAN) procedures arerequired to be designed such that different physical layerconfigurations can be operated efficiently by the UE without hamperingany of the service requirements. It is expected that single MediumAccess Control (MAC) entity could possible support multiple physicallayer configurations or numerologies simultaneously. Of course thisdepends on the capability of the UE hardware. This introduces newchallenges in terms of the physical layer operations such as HARQprocedures. For instance, in LTE and associated releases, only onenumerology is used across all carriers used in the carrier aggregationmechanism. Further, Physical Uplink Control Channel (PUCCH) on theprimary cell will carry the HARQ information for all the carriers.However, such a mechanism will not be useful for future wireless systems(i.e., 5G) when different numerologies may be considered for differentcarriers and even within a single carrier. The mechanisms are necessaryto efficiently support HARQ procedures.

Thus, it is desired to address the above mentioned disadvantages orother shortcomings or at least provide a useful alternative.

SUMMARY

The principal object of the embodiments herein is to provide a methodand UE for managing HARQ procedure for multiple numerologiesmultiplexing in a wireless communication network.

Another object of the embodiments herein is to provide a method forperforming a shared (i.e., combined) HARQ procedure in case of multiplenumerologies (e.g., comprising a plurality of different set ofnumerologies).

Another object of the embodiments herein is to provide a method forsupporting joint uplink control information (UCI) feedback foraggregated carriers with different numerology.

Another object of the embodiments herein is to provide a method forsupporting one PUCCH in one cell group for NR DC/CA, where each cellgroup comprises of an identical numerologies.

Another object of the embodiments herein is to provide HARQconfigurations such as HARQ processes, HARQ timing indications forfuture wireless systems.

Another object of the embodiments herein is to provide HARQ prioritybased mechanism to account for the traffic types in future wirelesssystems.

Accordingly the embodiments herein provide a method for managing formanaging HARQ procedure for multiple numerologies multiplexing in awireless communication network. The method includes transmitting, by aUser Equipment (UE), capability parameters of the UE to a Base Station(BS). Further, the method includes receiving, by the UE, a plurality ofHARQ configuration parameters corresponding to the capability parametersof the UE from the BS, and perfuming, by the UE, one of an individualHARQ process and a shared HARQ process based on the plurality of HARQconfiguration parameters received from the BS.

In an embodiment, the plurality of HARQ configuration parameterscomprises at least one of a HARQ timing configurations, a joinedHARQ-ACK codebook for performing the shared HARQ process, a groupidentifier representing a plurality of carriers corresponding to eachidentical numerology from multiple numerologies for performing theshared HARQ process, a service type and a plurality of serviceparameters.

In an embodiment, the service type and the plurality of serviceparameters are used for determining priority of the HARQ procedure toperform the shared HARQ process.

In an embodiment, the capability parameters of UE comprise at least oneUE minimum HARQ processing time, subcarrier spacing, TTI length, timingadvance (TA), maximum TBS, and UE power constraint and HARQ bufferconstraint.

In an embodiment, the HARQ timing configuration are received from the BSthrough one of a System Information Block (SIB) message, a RadioResource Control (RRC) message and a DCI message.

Accordingly, the embodiments herein provide a UE hybrid automatic repeatrequest (HARQ) procedure for multiple numerologies multiplexing. The UEcomprising a memory, a processor coupled to the memory, and a HARQprocedure executor configured to transmit capability parameters of theUE to a Base Station (BS). Further, the HARQ procedure executor isconfigured to receive a plurality of HARQ configuration parameterscorresponding to the capability parameters of the UE from the BS.Furthermore, the HARQ procedure executor is configured to perform one ofan individual HARQ process and a shared HARQ process based on theplurality of HARQ configuration parameters received from the BS.

These and other aspects of the embodiments herein will be betterappreciated and understood when considered in conjunction with thefollowing description and the accompanying drawings. It should beunderstood, however, that the following descriptions, while indicatingpreferred embodiments and numerous specific details thereof, are givenby way of illustration and not of limitation. Many changes andmodifications may be made within the scope of the embodiments hereinwithout departing from the spirit thereof, and the embodiments hereininclude all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS

This invention is illustrated in the accompanying drawings, throughoutwhich like reference letters indicate corresponding parts in the variousfigures. The embodiments herein will be better understood from thefollowing description with reference to the drawings, in which:

FIGS. 1A-1B illustrates an example of TDM numerology multiplexing inLTE-FDD system;

FIGS. 2A-2B illustrates an example of TDM numerology multiplexing inLTE-TDD systems with DL-UL configuration 0;

FIG. 3 illustrates a wireless communication system including a BS and aUE for managing HARQ procedure in case of multiple numerologies,according to embodiment as disclosed herein;

FIG. 4 is a flow diagram illustrating a method for managing hybridautomatic repeat request (HARQ) procedure for multiple numerologiesmultiplexing, according to embodiment as disclosed herein;

FIG. 5 is a flow diagram illustrating various steps performed by the BS(i.e., gNB) for indicating a plurality of HARQ configuration parametersto the UE corresponding to the capability parameters of the UE,according to an embodiment as disclosed herein; and

FIG. 6 is a flow diagram illustrating various steps performed by the BS(i.e., gNB) for indicating HARQ priority handling to the UE, accordingto an embodiment as disclosed herein.

DETAILED DESCRIPTION

Various embodiments of the present disclosure will now be described indetail with reference to the accompanying drawings. In the followingdescription, specific details such as detailed configuration andcomponents are merely provided to assist the overall understanding ofthese embodiments of the present disclosure. Therefore, it should beapparent to those skilled in the art that various changes andmodifications of the embodiments described herein can be made withoutdeparting from the scope and spirit of the present disclosure. Inaddition, descriptions of well-known functions and constructions areomitted for clarity and conciseness.

Also, the various embodiments described herein are not necessarilymutually exclusive, as some embodiments can be combined with one or moreother embodiments to form new embodiments. Herein, the term “or” as usedherein, refers to a non-exclusive or, unless otherwise indicated. Theexamples used herein are intended merely to facilitate an understandingof ways in which the embodiments herein can be practiced and to furtherenable those skilled in the art to practice the embodiments herein.Accordingly, the examples should not be construed as limiting the scopeof the embodiments herein.

Prior to describing the embodiments in detail, it is useful to providedefinitions for key terms used herein. Unless defined otherwise, alltechnical terms used herein have the same meaning as commonly understoodby a person having ordinary skill in the art to which this inventionbelongs.

Considering limited number of HARQ processes, it is necessary to handlethem efficiently, following are the HARQ procedure for multiplenumerologies multiplexing in future wireless communication systems.

Individual HARQ procedure: In response to receiving the HARQconfiguration parameters (i.e., HARQ processes, HARQ timing indications)from the BS, the UE can perform the individual HARQ procedure with cellsoperating in different subcarrier. For example, if the UE upondetermining that there is no latency in HARQ processes, determines thatthe HARQ transmission with the “A” cell operating at numerology-1 needsto be transmitted at n+4 sub-frame and the HARQ transmission with the“B” cell operating at numerology-2 needs to be transmitted at n+6sub-frame, then individual HARQ procedure with each cell can befollowed.

Shared HARQ procedure: In response to receiving the HARQ configurationparameters (i.e., HARQ processes, HARQ timing indications) from the BS,the UE can perform the shared HARQ procedure with cells operating indifferent subcarrier. For example, if the UE upon determining that thereis latency in HARQ processes/in case of power savings, a joint HARQcodebook can be followed across carriers with multiple numerologies(cell “A” and cell “B”) such that numerology aggregation is taken intoaccount. Further, the shared HARQ process is similar to slot aggregationdue to difference in numerologies.

As traditional in the field, embodiments may be described andillustrated in terms of blocks which carry out a described function orfunctions. These blocks, which may be referred to herein as units,manager, detector, engine, or modules or the like, are physicallyimplemented by analog and/or digital circuits such as logic gates,integrated circuits, microprocessors, microcontrollers, memory circuits,passive electronic components, active electronic components, opticalcomponents, hardwired circuits and the like, and may optionally bedriven by firmware and/or software. The circuits may, for example, beembodied in one or more semiconductor chips, or on substrate supportssuch as printed circuit boards and the like. The circuits constituting ablock may be implemented by dedicated hardware, or by a processor (e.g.,one or more programmed microprocessors and associated circuitry), or bya combination of dedicated hardware to perform some functions of theblock and a processor to perform other functions of the block. Eachblock of the embodiments may be physically separated into two or moreinteracting and discrete blocks without departing from the scope of thedisclosure. Likewise, the blocks of the embodiments may be physicallycombined into more complex blocks without departing from the scope ofthe disclosure.

Accordingly, the embodiments herein provide a method for managing formanaging HARQ procedure for multiple numerologies multiplexing in awireless communication network. The method includes transmitting, by aUser Equipment (UE), capability parameters of the UE to a Base Station(BS). Further, the method includes receiving, by the UE, a plurality ofHARQ configuration parameters corresponding to the capability parametersof the UE from the BS, and determining, by the UE, to perform one of anindividual HARQ process and a shared HARQ process based on the pluralityof HARQ configuration parameters received from the BS.

Unlike to conventional methods and conventional systems, the proposedmethod can be used to provide HARQ procedure for Multiple NumerologiesMultiplexing in Future Wireless Systems. The proposed method providesHARQ configurations such as HARQ processes, HARQ timing indications forfuture wireless systems. Further, the proposed method provides HARQpriority-based mechanism to account for the traffic types in futurewireless systems.

Referring now to figures, and more particularly to FIGS. 1 through 6,where similar reference characters denote corresponding featuresconsistently throughout the figures.

FIGS. 1A-1B illustrates an example of TDM numerology multiplexing inLTE-FDD system.

In LTE only one numerology is used for all Primary Cell (Pcell) andSecondary Cells (Scells). All the configuration parameters i.e., HARQ,UCI etc., for all the Scells is carried on only the Pcell (as they alloperate on the same timeline of frame structure etc.).

Referring to FIG. 1A, where the Pcell and the Scells operating at 15 kHzcarrier frequency, the UE receives DL transmissions in sub-frame “n” andfeeds back a signaling message indicating of whether the DL transmissionreceived at sub-frame “n” needs to be retransmitted i.e., feeds backAcknowledgement/Negative Acknowledgement (ACK/NACK) information in ULsub-frame at n+4 to both Pcell and the Scells. Thus, when carriers areaggregated, ACK/NACK information corresponding to a plurality of DLcarriers in sub-frame n+4 will be fed back in UL sub-frame nconcurrently.

Further, in response to transmitting the feedback signaling message, theUE can be configured to receive the DL potential re-transmission of thedata in sub-frame “n+8”.

The similar HARQ procedure is performed by the UE when the Pcell and theScells are operating at 30 kHz.

But in case of future wireless systems (e.g., NR i.e., 5G communicationssystems) different numerologies can be used on different carriers/cellsthat can be activated (for e.g., the Pcell operating on 15 KHz and theScells at operating at 30 kHz). Due to the use of carrier aggregation(CA), potentially with different numerologies where HARQ-ACK forcarriers using a shorter TTI need to occur on a carrier/cell using alonger TTI, the use of dynamic HARQ-ACK timing, and the potential use ofcode block based or code block group based HARQ-ACK, is expected. Asemi-static HARQ-ACK codebook determination will often lead to asignificant increase in resource overhead for achieving a target BLER.

Different carriers can use different numerologies such as differentsub-carrier spacing or different duration for a transmission which canbe optimal for that particular frequency depending on capability of theUE and the BS. The capability can be, for example, coverage and linkrobustness for higher frequency links such as mmWave links can beprovided by sending control transmissions on lower frequency links,while large bandwidths in higher frequencies can be used for massivedata transmissions.

Thus, similar HARQ process to that of LTE (in case of same numerologyi.e., both Pcell and Scells operating at 15 kHz/both Pcell and Scellsoperating at 30 kHz) cannot be optimal in the NR (i.e., 5G communicationsystem) incorporating multiple numerologies (i.e., Pcell operating at 15kHz and Scells operating at 30 kHz).

Further, in LTE, the HARQ-ACK codebook determination can be dynamicbased on DAI or semi-static (e.g. based on number of activated cells)and the UL slot for HARQ-ACK transmission by a UE has a fixed timingrelation relative to DL slot(s) of corresponding PDSCH receptions. Infuture wireless systems, both dynamic and semi-static HARQ-ACK codebookdetermination can be considered, and HARQ-ACK transmission timing can bedynamic as indicated by DCI formats that schedule corresponding PDSCH.Also, there are various types of HARQ procedures synchronous orasynchronous and adaptive vs non-adaptive. Any synchronous HARQprocedure does not have HARQ process and is tightly coupled with atimeline. Therefore, each transmission must stick to timeline and hencecannot share its timeline with anyone else. For example, uplink ismostly using synchronous HARQ procedures. On the other hand, whenasynchronous HARQ procedures can be used, they use a HARQ process id,HARQ codebook for following appropriate retransmission cycle.

As shown in the FIG. 1A, the numerology-1 (i.e., 15 KHz) has twice theTTI duration to that of the numerology-2 shown in the FIG. 1B. As thesymbol duration is inversely proportional to sub-carrier spacing fore.g., if the symbol duration for 15 kHz carrier is 67 μs then for 30 kHzcarrier the symbol duration would be 33 μs. Hence, if these numerologieshave to share the HARQ procedures, then the numerology-2 will have towait and thereby the latency increases. For e.g., location of actual A/Nfor is supposed to be sub-frame “n7=n3+4” (in case of shared HARQ 15 kHzand 30 kHz) but the joint A/N is transmitted at sub-frame “n10=n6+4”.Hence, experiencing the latency while performing the shared HARQprocedure.

Unlike to conventional method and systems, the proposed method can beused to manage the HARQ procedure in case of multiple numerologies.Further, the proposed method can be used to perform an efficient andfast joint HARQ procedure based on the HARQ configurations indicated toUE, thereby reducing the latency.

Unlike to conventional method and systems, the proposed method can beused to share the HARQ ID/codebook with other transmissions. Thus, theproposed method can be used to provide a joint HARQ codebook designacross carriers with multiple numerologies such that numerologyaggregation is taken into account.

FIGS. 2A-2B illustrates an example of TDM numerology multiplexing inLTE-TDD systems with DL-UL configuration 0.

In an example, a frame of ten milliseconds duration is divided into tensub-frames. A sub-frame can be uplink (UL), downlink (DL) or specialsub-frame. The UL and DL sub-frame ratio and number of specialsub-frames per frame varies according to the UL-DL configuration used.The available TD LTE UL-DL configurations are illustrated in the FIGS.2A-2B, where “D” denotes sub-frame reserved for DL transmissions, “U”denotes sub-frame reserved for UL transmissions and “S” denotes aspecial sub-frame. The special sub-frame is used for switching betweenDL and UL sub-frames.

Similar problem, as described above in case of LTE-FDD systems persistsin the LTE-TDD systems with DL/UL configuration 0 (as shown in FIGS.2A-2B). The latency needs to be accounted, if the sharing of the HARQhas to be performed.

Unlike to conventional methods and conventional systems, the proposedmethod can be used to perform the shared HARQ procedure (i.e., in caseif the latency is not an issue and the numerology multiplexing isallowed). Otherwise, individual HARQ procedure are preferred. For caseof power savings, shared HARQ procedure can be used. Considering all theinvolved tradeoffs, either shared or individual HARQ processes may beused.

Unlike to conventional method and systems, the proposed method can beused to provide a single HARQ process per numerology configuration incase of numerology multiplexing in single carrier.

Unlike to conventional method and systems, the proposed method be usedto effectively manage the HARQ processes, as the HARQ processes islimited for each UE.

FIG. 3 illustrates a wireless communication system 300 including a BS100 and a UE 200 for managing HARQ procedure in case of multiplenumerologies, according to embodiment as disclosed herein.

Referring to FIG. 3, the wireless communication system 300 includes theBS 100 communicating with the UE 200. In an embodiment, the wirelesscommunication system 300 may include, for example, an evolved universalterrestrial radio access network (EUTRAN), wireless metropolitan areanetworks (WMAN), a wireless local area network (WLAN), wireless personalarea network (WPAN). The wireless communication system 300 can supportvarious wireless technologies such as, for e.g., global system formobile communications (GSM), enhanced data rates for GSM evolution(EDGE), GSM EDGE radio access network (GERAN), universal mobiletelecommunications system (UMTS), UMTS terrestrial radio access network(UTRAN), or other 2G, 3G, 4G, 5G, etc. technologies either alreadydeveloped or to be developed.

In an embodiment, the BS 100 can include, for example, base transceiverstation (BTS), evolved Node B (eNB), a generation Node B (gNB), amacrocell, microcell, a picocell, a femtocell, etc.

In an embodiment, the UE 200 can include, for example, a cellular phone,a smart phone, a session initiation protocol (SIP) phone, a laptop, apersonal digital assistant (PDA), a satellite radio, a globalpositioning system, a multimedia device, a video device, a digital audioplayer (e.g., MP3 player), a camera, a game console, a tablet, anotebook, a smart book, an ultrabook, or any other similar functioningdevice. The UE 200 can also be, for example, a mobile station, asubscriber station, a mobile unit, a subscriber unit, a wireless unit, aremote unit, a mobile device, a wireless device, a wirelesscommunications device, a remote device, a mobile subscriber station, anaccess terminal, a mobile terminal, a wireless terminal, a remoteterminal, a handset, a user agent, a mobile client, a client, or someother suitable terminology.

In an embodiment, the UE 200 includes a RF transceiver 220, a HARQprocedure executor 230, a processor 240 and a memory 250.

The RF transceiver 220, coupled with antenna 210, can be configuredcommunicate with various other apparatus over a transmission medium. Thevarious other apparatus includes, for e.g., network, and any other UE(not shown). The network can include, for example, any of theaforementioned BS 100.

The RF transceiver 220 can be configured to transmit a plurality of UEcapability parameters to the BS 100. The plurality of UE capabilityparameters can include, for example, at least one UE minimum HARQprocessing time, subcarrier spacing, TTI length, timing advance (TA),maximum TB S, soft buffer limitations, and UE power constraint. The UEcapability parameters can be indicated in terms “N1” and “N2” symbols.For example, consider “N1” to be most relevant according to aspect ofthe present embodiments.

In case of UE 200 for scheduling in consecutive slots, the number ofHARQ processes should be determined by a HARQ re-transmission timer(HTT) (not shown). For example, if the HARQ RTT is 8 slots, then thenumber of HARQ processes for the UE 200 should be at least 8 forcontiguous data scheduling. In LTE, each UE category defines soft buffersize and maximum number of data bits that the UE 200 can receive in theTTI. The maximum number of data bits that the UE 200 can receive in theTTI can be derived by maximum TBS and supported number of cell groups(CGs)/cells (i.e., reported by UE 200 as UE capability parameters).

Even for the same maximum number of data bits per TTI, the maximum TBSand the supported number of CGs may not be fixed. The above factors suchas the soft buffer size and maximum TBS can affect HARQ RTT. RegardingHARQ RTT, the UE 200 can report its capability to the gNB. Therefore,the number of HARQ processes that the UE 200 supports may be related tohow the UE 200 categories are defined in the NR. Further, the number ofHARQ processes supported by the UE 200 is indicated by the UE 200 to theBS 100.

In response to transmitting the plurality of UE capability parameters,the HARQ procedure executor 230, coupled to the RF transceiver 210, canbe configured to receive a plurality of HARQ configuration parametersfrom the BS 100. In an embodiment, the HARQ procedure executor 230 canbe configured to receive the plurality of HARQ configuration from the BS100. In an embodiment, the plurality of UE capability parametersincludes, for example, at least one of a HARQ timing configurations, ajoined HARQ-ACK codebook for performing the shared HARQ process, a groupidentifier representing a plurality of carriers corresponding to eachidentical numerology from multiple numerologies for performing theshared HARQ process, a service type and a plurality of serviceparameters.

In an embodiment, the UE 200 can be configured to receive the pluralityof HARQ configuration parameters through a System Information Block(SIB) message, a Radio Resource Control (RRC) message and a DownlinkControl Indicator (DCI) message.

Another interesting problem is whether or not HARQ retransmissions canbe performed across numerologies i.e., when the first transmission is onnumerology 1 but the corresponding re-transmission is on numerology 2.Note that if the mother code for the different transmissions isdifferent than HARQ is not possible across different numerologies sincecombining of the data must be performed by the receiver. However, whenthe mother code is the same, re-transmissions can be performed in adifferent numerology compared to first transmission if found necessary.When multiple HARQ Ack bits per TB is supported for the future wirelesssystems, in which case a CB alone may be re-transmitted. When thecarrier and bandwidth used for transmission and re-transmission are thesame, the benefits of using a different numerology only to address thechannel effects may not be much. However, if there is a possibility thatthe bandwidth used for re-transmission may be adapted, specifically inthis case increased when compared to the first transmission, thenretransmission on a different numerology can help to fasten theprocedures. The HARQ entity is something maintained at the MAC layer. Ifthe HARQ retransmission is not performed across different numerologies,it can be modeled that at least one HARQ entity is linked per numerologyper carrier. Therefore, numerology specific HARQ can be configured, inother words, the BS 100 may indicate no HARQ retransmission is allowedacross various numerologies. However, HARQ entity can be shared acrossnumerologies when re-transmissions are allowed across differentnumerologies. The HARQ configurations can be asymmetric between the basestation and UE side depending on the numerologies used at each end andtheir respective abilities. In such cases, polling based HARQ procedureswherein each node requests the other node at a specific time duration tosend the HARQ for all previous time durations can be used.

HARQ Timing: In an embodiment, for dynamic HARQ timing, a fully dynamicsignaling can be used via DCI. Another mechanism is to make it RRC andDCI controlled where RRC configures a set of potential timing offsetswithin which the UE 200 will be prepared ahead of time and DCI canspecifically configure one of these offsets. This can provide morecontrolled asynchronous HARQ procedure for future wireless systems. Forinstance, the RRC configured offsets for HARQ procedures can considerthe timelines of the various numerologies involved and think aboutpotential re-transmission durations as shown in the FIGS. 1, 2 and 3 asdescribed above. Then DCI can exactly indicate the re-transmission timebased on latency, priority etc. Another mechanism wherein a default HARQtimeline can be configured by the BS 100 as part of the SystemInformation Block (SIB) messages. Therefore, (i) SIB, (ii) RRC and (iii)DCI based mechanisms can be considered for configuring the HARQtimelines and configurations. Switching between these configurations ispossible. The SIB-based configuration can be changed everysi-modification period instances. Hence, (i) static, (ii) semi-staticand (iii) dynamic mechanisms for HARQ timing are considered for futurewireless technologies.

Also, since symbol length and TTI depends on subcarrier spacing i.e.numerology, minimum HARQ processing time would be dependent onnumerology. When the UE 200 decides its capability of minimum HARQprocessing time, the UE 200 should consider subcarrier spacing, TTIlength, timing advance (TA), and maximum TBS and indicate to the BS 200at prior. When self-contained slot structures are being considered forfuture wireless systems, in extreme latency cases, HARQ may be sentwithin the same slot.

Considering such a design for future wireless systems, the total numberof HARQ processes need not be limited as in LTE. Specifically, severalHARQ processes are required to run in parallel so that the transmissionof TBs continues while the receiver is decoding already received TBs.For future wireless systems, it can be configurable based on UE ability,number of numerologies supported, service type (eMBB may support largenumber of HARQ processes while URLLC needs smaller number of HARQprocesses to avoid much latency) etc. In fact, the total number of HARQprocesses that are used depend on total number of cells/numerologies/TTIdurations the UE 200 can support as well as processing time for eachnumerologies/TTI durations. But this is also tied up with the softbuffer size limitations at each node. Since the amount of data to bestored for large number of HARQ processes linearly scales the softbuffer size and memory, a tradeoff exists. It is better to define asmall soft buffer size with large number of HARQ processes.

When the number of HARQ processes is very large, and HARQ bundling isused, the coding gains can be better since the size of the payloads arelarger. In such cases the latency increases. Hence, a choice can be madeas to how many HARQ bits can be bundled based on the coding mechanismsuch as TBCC/Reed Muller or polar codes used for encoding thePUCCH/PDCCH data where this is sent. This is because each of these codesbehaves better at a different number of bits in the payload. Hence, ajoint design is necessary for the same.

NACK-based HARQ procedures: Usually in LTE, Ack is sent for every wellreceived packet. In good channel conditions, a lot of Acks will have tobe sent. IN such cases, the base station and UE can decide to switch toa NACK-based protocol where a NACK is sent only for un-successful packet(both UL and DL) and thereby save the resources. This switching can bedynamic manner when the mobile conditions are fast varying. In caseswhere UE is not moving, then semi-static RRC-based reconfiguration canalso be used.

In an embodiment, the HARQ procedure executor 230 can include, forexample, a HARQ configuration parameter analyzer 232, a HARQ proceduredetermination engine 234, and a HARQ priority analyzer 236.

In an embodiment, the HARQ configuration parameter analyzer 232 can beconfigured to analyze the plurality of HARQ configuration parametersreceived from the BS 100. For e.g., the HARQ configuration parameteranalyzer 232 can analyze (example, decode) signaling messages includingthe HARQ configuration parameters to identify HARQ timeline to befollowed by the UE 200.

This is to say that in all these cases, the reference timing can be thePcell/Scell depending on the implementation and the BS 100 networkloading. The timeline can be maintained either based on the Pcell/Scellor any other cell. As long as the Scell follows reference numerology andthen that reference timeline can be maintained. This can also beindicated based on the maximum number of cells for the UE 200 toidentify which timeline must be used in case sharing of the HARQ processis to be allowed. For example if only 2 cells are used then the Pcelland Scell, then “1” bit can be used as “0” or “1” to indicate the UE 200to follow the Pcell numerology/Scell numerology. The BS 100 canconfigure the UE 200 based on the new timeline.

In an embodiment, the HARQ procedure determination engine 234 can beconfigured to determine whether to perform the individual HARQ procedureor the HARQ sharing procedure based on the output indicated by the HARQconfiguration parameter analyzer 232. For e.g., if the HARQconfiguration parameter analyzer 232 determines that the there is noHARQ process and soft buffer limit, then HARQ procedure determinationengine 234 can be configured to perform the individual HARQ procedureelse the shared HARQ procedure is performed.

In an embodiment, for the shared HARQ procedure the HARQ codebook isjointly designed.

In LTE there is a concept of cell group for which all uplink controlinformation is sent jointly. Similarly for the future wireless systemssince varied numerologies can be used across varied numbers of carriers,cell groups are identified based on the numerologies used on variouscarriers and inside each of these cell groups one carrier will bedesignated as the Pcell group carrier which will carry UCI for all thecells/carriers in this group on same numerology. However, when this isnot feasible and the network mandates the UE 200 to send only on onedesignated Pcell, then the UCI scheduling should account for the variousnumerologies, latencies involved etc. of all TTI durations correspondingto all numerologies.

Thus, the proposed method can be used to support one PUCCH in one cellgroup for NR DC/CA. Further, the proposed method allows the wirelesscommunication system 100 to support at least the configuration of onecarrier transmitting the PUCCH within the cell group.

In an embodiment, when the UE 200 is configured with carrier aggregationfor cells with different numerologies/slot durations, such as a firstslot duration and a second slot duration, and with HARQ-ACK transmissionon the PUCCH of a cell using the first slot duration (say Pcell),HARQ-ACK timing for HARQ-ACK transmission on a cell using the secondslot duration can be with respect to the first slot duration. Regardlessof FDD or TDD operation, the first slot duration is P times longer thanthe second slot duration, then the HARQ-ACK codebook determination thefirst slot duration corresponds to a bundling window with size of Pslots for cells using the second slot duration. Note that this operationcan resemble the one in LTE for FDD-TDD CA or TDD CA with differentUL-DL configurations. For the operation of a DAI field, cells usingdifferent slot durations can be divided into respective groups accordingto the slot duration. A value of a DAI field in a DL DCI format is setwith respect to cells with same slot duration.

Further, the HARQ priority analyzer 236 can be configured to provideHARQ priority-based mechanism to account for the traffic types in thefuture wireless systems (5G).

In order to support proper operations of the URLLC and to account forits low latency aspects, a separate HARQ processes is preferred.Although asynchronous HARQ is used for the future wireless systems maybe used, some form of HARQ priority may be needed in such cases toensure low latency services are not impacted. Although in LTE there wasno HARQ process prioritization defined to deal with potential softbuffer overflow, there is a need to define such priorities in futurewireless systems according to traffic type and configuration by thenetwork is a reasonable approach. If services are of equal priority,then the BS 100 can in a round-robin fashion cycle the priorities forfairness considerations.

For example, the HARQ priority analyzer 236 can be configured to assignHARQ priority based on the indications (by determining the plurality ofthe service parameters) received from the BS 110, following are theexample of the plurality of the service parameters: a) SR/BSR-based, b)buffer overflow statuses, c) channel conditions (better channelcondition can finish its transmission fast and then allow for longre-transmission cycles of bad channel conditions devices), d) beamtraining periods (which can be indicative of channel quality in mmWavebeamforming systems), e) coverage levels identified using RSRP/RSRQ, f)data type (voice/video/public safety etc.,) g) QoS requirements h) theUE capability (low power UE has more priority than high power UE), amongothers.

Some new bits for HARQ priority may have to be added. The number of bitsis received by the UE 200 in the PDCCH from the BS 100, where each bitindicates the timing of HARQ transmission. The number of bits depends onnumber of numerologies that the UE 200 can support simultaneously ornumber of CGs defined for the future wireless systems. This can definethe PDCCH format that the UE 200 will have to receive. For example, adifferent PDCCH format can be used to indicate this number of bitsdepending on the size of the bits used for HARQ priority indication.

The processor 240 can be configured to execute the instructions receivedfrom the other hardware components of the UE 200.

The memory 250 can be, for e.g., a computer-readable medium such as amagnetic storage device (e.g., hard disk, floppy disk, magnetic strip),an optical disk (e.g., compact disc (CD), digital versatile disc (DVD)),a smart card, a flash memory device (e.g., card, stick, key drive),random access memory (RAM), read only memory (ROM), programmable ROM(PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), aregister, or a removable disk. Although memory is shown separate fromthe processors in the various aspects presented throughout thisdisclosure, the memory may be internal to the processors (e.g., cache orregister).

FIG. 4 is a flow diagram illustrating a method 400 for managing HARQprocedure for multiple numerologies multiplexing, according toembodiment as disclosed herein.

At step 402, the method includes transmitting the capability parametersof the UE 200 to the BS 100. In an embodiment, the method allows the RFtransceiver 210 to transmit the capability parameters of the UE 200 tothe BS 100.

At step 404, the method includes receiving the plurality of HARQconfiguration parameters corresponding to the capability parameters ofthe UE 200 from the BS 100. In an embodiment, the method allows the HARQprocedure executor 230 to receive the plurality of HARQ configurationparameters corresponding to the capability parameters of the UE 200 fromthe BS 100.

At step 406, the method includes performing one of the individual HARQprocess and the shared HARQ process based on the plurality of HARQconfiguration parameters received from the BS 100. In an embodiment, themethod allows the HARQ procedure determination engine 234 to perform oneof the individual HARQ process and the shared HARQ process based on theplurality of HARQ configuration parameters received from the BS 100.

FIG. 5 is a flow diagram 500 illustrating various steps performed by theBS (i.e., gNB) for indicating a plurality of HARQ configurationparameters to the UE corresponding to the capability parameters of theUE, according to an embodiment as disclosed herein. At step 502, themethod includes determining carrier aggregation (CA) configuration basedon UE capability. At step 504, the method includes determining singlecarrier numerology multiplexing for UE based on UE capability. At step506, the method includes determining the HARQ process limitations at theUE 200 are determined based on the UE capability information, then theBS 100 indicates the UE to perform individual HARQ procedure or sharedHARQ procedure based on the capability parameters of the UE 200.

At step 508 a and 508 b, the BS 100 determines and indicates whether toperform individual HARQ procedure or shared HARQ procedure through HARQconfiguration parameters. At step 510 a, the BS provides cell groupdefinition for the CA based on numerology, in which the BS 200 assigns agroup identifier representing a plurality of carriers corresponding toeach identical numerology from multiple numerologies for performing theshared HARQ procedure. At step 512 a, a PUCCH per group of carriers withsame numerology is assigned and accordingly HARQ timeline decision isindicated to the UE 200 at step 514 a.

In case of single carrier numerology, the BS 100 defines referencenumerology at step 510 b. Further, at step 512 b, the BS 100 assignsPUCCH numerology and accordingly HARQ timeline decision is indicated tothe UE 200 at step 514 b.

FIG. 6 is a flow diagram 600 illustrating various steps performed by theBS (i.e., gNB) for indicating HARQ priority handling to the UE,according to an embodiment as disclosed herein.

At step 602, the BS 100 determines the shared HARQ procedure based oncapability parameters of the UE 200. At step 604, the BS 100 determineswhether to provide HARQ priority based on configuration of BS 100. Incase, the BS 100 determines that there is no HARQ priority to beprovided to the UE 200, then at step 606, the BS 100 provides Joint HARQtimeline/codebook design across numerologies/services. In case, the BS100 determines to provide HARQ priority to the UE 200, at step 608, theBS 100 indicates HARQ priority to the UE. At step 610, the HARQ timingconfigurations are indicated to the UE 200 through one of the SIBmessage, a RRC message and a Downlink Control Indicator (DCI) messageand a MAC message.

The embodiments disclosed herein can be implemented through at least onesoftware program running on at least one hardware device and performingnetwork management functions to control the elements. The elements shownin the FIGS. 1 through 6 include blocks which can be at least one of ahardware device, or a combination of hardware device and software units.

The foregoing description of the specific embodiments will so fullyreveal the general nature of the embodiments herein that others can, byapplying current knowledge, readily modify or adapt for variousapplications such specific embodiments without departing from thegeneric concept, and, therefore, such adaptations and modificationsshould and are intended to be comprehended within the meaning and rangeof equivalents of the disclosed embodiments. It is to be understood thatthe phraseology or terminology employed herein is for the purpose ofdescription and not of limitation. Therefore, while the embodimentsherein have been described in terms of preferred embodiments, thoseskilled in the art will recognize that the embodiments herein can bepracticed with modification within the spirit and scope of theembodiments as described herein.

What is claimed is:
 1. A method performed by a user equipment (UE), themethod comprising: receiving, from a base station, a first downlinksignal; receiving, from the base station, a second downlink signal afterreceiving the first downlink signal; determining whether to multiplexfirst hybrid automatic repeat request (HARQ)-acknowledge (ACK)information for the first downlink signal and second HARQ-ACKinformation for the second downlink signal in a slot or not, based on aHARQ processing time and a timing associated with the second downlinksignal relative to the slot; and in case that the first HARQ-ACKinformation and the second HARQ-ACK information are multiplexed in theslot, transmit, to the base station, an uplink signal including thefirst HARQ-ACK information and the second HARQ-ACK information on theslot.
 2. The method of claim 1, wherein the first downlink signal isassociated with a first subcarrier spacing and the second downlinksignal is associated with a second subcarrier spacing, and wherein theHARQ processing time is determined based on at least one of the firstsubcarrier spacing or the subcarrier spacing.
 3. The method of claim 1,wherein the HARQ processing time depends on a capability of the UE. 4.The method of claim 1, wherein the slot is identified based on a firstoffset indicated by first downlink control information (DCI) in thefirst downlink signal, wherein the first offset is used to indicate anuplink timing for the first HARQ-ACK information relative to physicaldownlink shared channel (PDSCH) reception scheduled by the first DCI inthe first downlink signal, wherein the slot is identified based on asecond offset indicated by second DCI in the second downlink signal, andwherein the second offset is used to indicate an uplink timing for thesecond HARQ-ACK information relative to PDSCH reception scheduled by thesecond DCI in the second downlink signal.
 5. The method of claim 1,further comprising: in case that the first HARQ-ACK information and thesecond HARQ-ACK information are not multiplexed in the slot,transmitting, to the base station, an uplink signal including one of thefirst HARQ-ACK information and the second HARQ-ACK information on theslot.
 6. A method performed by a base station, the method comprising:transmitting, to a user equipment (UE), first downlink signal;transmitting, to the UE, second downlink signal after receiving thefirst downlink signal; and receiving, from the UE, an uplink signal on aslot, wherein, in case that the first hybrid automatic repeat request(HARQ)-acknowledge (ACK) information for the first downlink signal andsecond HARQ-ACK information for the second downlink signal aremultiplexed in the slot or not, the uplink signal includes the firstHARQ-ACK information and the second HARQ-ACK information on the slot,and wherein, the multiplexing of the first HARQ-ACK information and thesecond HARQ-ACK information is determined based on a HARQ processingtime and a timing associated with the second downlink signal relative tothe slot.
 7. The method of claim 6, wherein the first downlink signal isassociated with a first subcarrier spacing and the second downlinksignal is associated with a second subcarrier spacing, and wherein theHARQ processing time is determined based on at least one of the firstsubcarrier spacing or the subcarrier spacing.
 8. The method of claim 6,wherein the HARQ processing time depends on a capability of the UE. 9.The method of claim 6, wherein the slot is identified based on a firstoffset indicated by first downlink control information (DCI) in thefirst downlink signal, wherein the first offset is used to indicate anuplink timing for the first HARQ-ACK information relative to physicaldownlink shared channel (PDSCH) reception scheduled by the first DCI inthe first downlink signal, wherein the slot is identified based on asecond offset indicated by second DCI in the second downlink signal, andwherein the second offset is used to indicate an uplink timing for thesecond HARQ-ACK information relative to PDSCH reception scheduled by thesecond DCI in the second downlink signal.
 10. The method of claim 6,wherein, in case that the first HARQ-ACK information and the secondHARQ-ACK information are not multiplexed in the slot, the uplink signalincludes one of the first HARQ-ACK information and the second HARQ-ACKinformation on the slot.
 11. A user equipment (UE) comprising: at leastone transceiver; and at least one processor coupled to the at least onetransceiver, wherein the at least one processor is configured to:receive, from a base station, a first downlink signal, receive, from thebase station, a second downlink signal after receiving the firstdownlink signal, determine whether to multiplex first hybrid automaticrepeat request (HARQ)-acknowledge (ACK) information for the firstdownlink signal and second HARQ-ACK information for the second downlinksignal in a slot or not, based on a HARQ processing time and a timingassociated with the second downlink signal relative to the slot, and incase that the first HARQ-ACK information and the second HARQ-ACKinformation are multiplexed in the slot, transmit, to the base station,an uplink signal including the first HARQ-ACK information and the secondHARQ-ACK information on the slot.
 12. The UE of claim 11, wherein thefirst downlink signal is associated with a first subcarrier spacing andthe second downlink signal is associated with a second subcarrierspacing, and wherein the HARQ processing time is determined based on atleast one of the first subcarrier spacing or the subcarrier spacing. 13.The UE of claim 11, wherein the HARQ processing time depends on acapability of the UE.
 14. The UE of claim 11, wherein the slot isidentified based on a first offset indicated by first downlink controlinformation (DCI) in the first downlink signal, wherein the first offsetis used to indicate an uplink timing for the first HARQ-ACK informationrelative to physical downlink shared channel (PDSCH) reception scheduledby the first DCI in the first downlink signal, wherein the slot isidentified based on a second offset indicated by second DCI in thesecond downlink signal, and wherein the second offset is used toindicate an uplink timing for the second HARQ-ACK information relativeto PDSCH reception scheduled by the second DCI in the second downlinksignal.
 15. The UE of claim 11, wherein the at least one processor isfurther configured to: in case that the first HARQ-ACK information andthe second HARQ-ACK information are not multiplexed in the slot,transmit, to the base station, an uplink signal including one of thefirst HARQ-ACK information and the second HARQ-ACK information on theslot.
 16. A base station comprising: at least one transceiver; and atleast one processor coupled to the at least one transceiver, wherein theat least one processor is configured to: transmit, to a user equipment(UE), first downlink signal, transmit, to the UE, second downlink signalafter receiving the first downlink signal, and receive, from the UE, anuplink signal on a slot, wherein, in case that the first hybridautomatic repeat request (HARQ)-acknowledge (ACK) information for thefirst downlink signal and second HARQ-ACK information for the seconddownlink signal are multiplexed in the slot or not, the uplink signalincludes the first HARQ-ACK information and the second HARQ-ACKinformation on the slot, and wherein, the multiplexing of the firstHARQ-ACK information and the second HARQ-ACK information is determinedbased on a HARQ processing time and a timing associated with the seconddownlink signal relative to the slot.
 17. The base station of claim 16,wherein the first downlink signal is associated with a first subcarrierspacing and the second downlink signal is associated with a secondsubcarrier spacing, and wherein the HARQ processing time is determinedbased on at least one of the first subcarrier spacing or the subcarrierspacing.
 18. The base station of claim 16, wherein the HARQ processingtime depends on a capability of the UE.
 19. The base station of claim16, wherein the slot is identified based on a first offset indicated byfirst downlink control information (DCI) in the first downlink signal,wherein the first offset is used to indicate an uplink timing for thefirst HARQ-ACK information relative to physical downlink shared channel(PDSCH) reception scheduled by the first DCI in the first downlinksignal, wherein the slot is identified based on a second offsetindicated by second DCI in the second downlink signal, and wherein thesecond offset is used to indicate an uplink timing for the secondHARQ-ACK information relative to PDSCH reception scheduled by the secondDCI in the second downlink signal.
 20. The base station of claim 16,wherein, in case that the first HARQ-ACK information and the secondHARQ-ACK information are not multiplexed in the slot, the uplink signalincludes one of the first HARQ-ACK information and the second HARQ-ACKinformation on the slot.